COMPARATOR CIRCUIT AND DISPLAY DEVICE PROVIDED THEREWITH

摘要

An inverter (15) is constituted using double gate TFTs (11, 12), and an inverter (16) is constituted using double gate TFTs (13, 14). Top gate terminals of the TFTs constituting the inverter (15) are connected to an input terminal (DAT) (+), and the bottom gate terminals are connected to the output and the output terminal OUT of the inverter (16). Bottom gate terminals of the TFTs constituting the inverter (16) are connected to an input terminal (DAT) (-), and the bottom gate terminals are connected to the output of the inverter (15). This controls the threshold voltages of the inverters (15, 16) to accelerate switching operation of the respective inverters, thereby causing the comparator circuit (10) to operate at high speed. Therefore, the comparator circuit obtained is resistant to the dispersion of the threshold voltage of a transistor and the fluctuation of the common mode voltage of an input signal and operates at high speed.